Experts say that Brazil is looking to expand energy ties with Nigeria, Africa's top oil producer, to fuel its growing economy.

At a major industry conference in Abuja last month, Nigeria's Oil Minister Diezani Alison-Madueke said that growing oil and gas production in the United States had begun affecting Nigerian exports and that the west African nation would have to look to different markets.

The fall is US exports was due in part to a rise in American shale oil production, including through new technologies like fracking, Alison-Madueke said.

Rousseff arrived in Nigeria after attending the Africa-South America summit in Equatorial Guinea, also a significant west African oil producer.